This project focuses on the characteristics of audio narration for understanding multimedia in eHealth by seniors and others, using cancer prevention as the subject matter. Multimedia is an increasingly popular method for presenting cancer and other health information on the web and via CD/DVD. However, there is virtually no health literacy research on effective strategies for the design of multimedia. For example, in the 187 design guidelines published in NIH's Research-Based Web Design and Usability Guidelines, multimedia is briefly mentioned in just 4 guidelines. This project will address this significant yet understudied area of health literacy. Segments of the population are affected differentially by a multimedia presentation. Many older adults experience difficulties understanding speech due to changes in hearing sensitivity and cognition that affect speech processing. The conversational style of speech that is typically used in eHealth multimedia is very difficult for many persons to understand. Thus information that is critical to health decision processes may be missed. The speech produced when a speaker intentionally tries to improve intelligibility by speaking slowly and clearly, but without exaggeration, is called "Clear Speech". Clear Speech style has been repeatedly shown to enhance intelligibility of speech in numerous studies over the past 20 years. The goal of this project is to systematically evaluate the effectiveness of Clear Speech as a narration technique for eHealth multimedia for seniors and to disseminate the results through guidelines. The overall design of the study will be a mixed factorial with age as a between-subject variable and performance on tasks as a within-subject variable. The study will be divided into intelligibility, comprehension, retention and preference testing. 40 senior and 20 younger adults will participate in the project. Clear Speech narration is expected to be proven to be a cost-effective strategy to significantly enhance the ability of millions of consumers to obtain, process, and understand health information presented in eHealth programs.